Less than 24 hours after being sentenced to 35 years in prison, Bradley Manning, the Army private convicted for leaking classified documents, made an unexpected announcement to the American public. "I am Chelsea Manning," Manning said in a statement read on the TODAY show this morning. "I am female. Given the way that I feel, and have felt, since childhood, I want to begin hormone therapy as soon as possible."

In the past, a transgender prisoner like Manning would have been especially vulnerable to sexual violence. That may be changing, thanks to the Prison Rape Elimination Act (PREA). Although the law was passed by Congress 10 years ago, it was enforced for the first time earlier this week, when every state in the country had to demonstrate compliance with the new set of federal regulations. The regulations were shaped by extensive research and graphic testimonies showing that gay and transgender prisoners were at particular at risk of victimization.

The reforms are particularly good news for male-to-female transgender inmates like Manning who, historically, have been housed with men in jails and prisons. These trans women, many of whom have breasts and feminine appearances, are frequently exposed to unwanted sexual attention and abuse from male staff and inmates. They are particularly vulnerable in settings like communal showers, and they often find themselves targeted for unnecessary pat-downs and strip searches.

Part of the problem is that most jails and prisons have never before used the word "transgender" in any written policies. The first step taken by the new PREA rules is to define some basic terms: gender identity (internal sense of feeling male or female); transgender (a person whose gender identity is different from his or her assigned sex at birth); gender nonconforming (a person whose appearance or manner does not match up with traditional societal gender expectations); and intersex (a person whose sexual or reproductive anatomy or chromosomal pattern does not fit typical definitions of male or female).

After acknowledging all of these variations, the new PREA rules address the question of whether to house transgender inmates with males or females. Jails, prisons, and juvenile facilities are now required to determine on a case-by-case basis whether a trans inmate will be safer housed with men or with women, and must give serious consideration to the inmate's own views regarding his or her safety. Importantly, the label "transgender" is not reserved for those who have undergone surgery or hormone treatment; it's based solely on a person's internal sense of feeling male or female. This means a trans woman like Manning cannot be excluded from protection because she has a penis, or because the prison administrator making housing decisions thinks she doesn't look "female enough".

Notably, trans men (female-to-male) inmates -- even those with facial hair and surgically altered chests -- may choose to remain with women because they feel safer from sexual victimization there. For that reason, there are no one-size-fits-all rules about housing. Instead, prison authorities must focus on minimizing risk of sexual victimization on a case-by-case basis, and ensuring that transgender inmates feel safe.

The housing decision rule also applies to inmates who were born with intersex conditions, including people with atypical genitalia (not clearly identifiable as male or female), those whose genitals look male or female on the outside but who have different internal organs (e.g., a phallus on the outside and a uterus and ovaries on the inside), and those with typical male or female organs whose chromosomes do not match their appearance (e.g., a person who appears physically to be male but has XX or XXY chromosomes).

The PREA rules also include new policies related to showers, pat-downs, and strip searches. Transgender inmates and those born with intersex conditions must be allowed to shower separately from other inmates if they wish. Searches must be conducted in the least intrusive manner possible, and staff must undergo specific training on how to conduct searches of trans people in a respectful and professional manner. The PREA rules prohibit any searches or physical exams whose purpose is solely to determine a person's genital status.

Although not required by the new PREA rules, some prison systems are going further to address respectful treatment of transgender inmates. They ensure, for instance, that housing decisions are made before the inmate is automatically given a male haircut. They ask authorities to provide the institutional clothing that the inmate prefers and call trans inmates by the first names and pronouns they request. They also ensure that physicians and nurses are knowledgeable and non-judgmental about gender identity and healthcare related to gender transition, providing treatment in accordance with accepted professional standards.

The predominance of "drop-the-soap" jokes has also contributed to the problem. Concluding his testimony to the PREA commission, a prisoner from Louisiana stated, "I often hear that homosexuals just love being in jail. That it is akin to a kid in a candy store. That... is so far from the truth. When I choose to be with someone, it's personal and intimate. Being raped is anything but. Jail is a nightmare for anyone. But for a gay man - the target of sexual assaults - it is pure hell."

Close supervision is particularly crucial when it comes to teenage prisoners. Because of their smaller size, adolescents in adult jails and prisons are extremely vulnerable to sexual victimization, especially when they identify as LGBT. Although teenagers represent a small percentage of inmates in adult facilities, they account for a very large portion of prison rape victims. Prison administrators often try to protect them by placing them in what amounts to long-term solitary confinement. Young people who are isolated and deprived of social contact are known to experience intense agitation, hopelessness, paranoia, hallucinations, and other signs of mental health deterioration. In fact, those who are held in adult facilities are 36 times more likely to commit suicide while in custody than their same-age peers in juvenile facilities.

Reform advocates pushed the Justice Department to use the Prison Rape Elimination Act as a vehicle to remove kids from adult facilities nationwide and require states to house them in juvenile facilities, whether they were tried as juveniles or as adults. Although this policy didn't make it into the final PREA regulations, the rules do focus on separating youth from adults in jails and prisons and warn administrators not to rely on solitary confinement to protect youth from sexual violence.

Meanwhile, sexual abuse happens in juvenile prisons too . In the past, staff have often let this harassment go unchecked, assuming that LGBT youth posed a danger to their peers. Little, if any, counseling was provided to affirm and support of LGBT identity.

But the PREA rules apply to juvenile prisons, too. In order to maintain federal funding, these facilities are now training staff to communicate professionally with LGBT youth. They are prohibiting employees from using terms that convey hatred, contempt, or prejudice, or imply that youth are abnormal or sinful. They are hiring and scheduling more staff to better supervise youth. They are also holding staff accountable for reporting abuse and harassment, and requiring them to take immediate measures to protect those being victimized.

Taken together, these policies and training requirements are more comprehensive than those required in most schools and workplaces. It may be a while before LGBT inmates are truly free from harassment. But if Chelsea Manning plans to live out her 35-year prison sentence as a woman, she is beginning that process at a particularly hopeful time.